#marspathfinder — Public Fediverse posts

No, I did not forget it. The APXS sensor was not deployed properly and data was taken basically of the atmosphere, not the surface (if anything was obtained at all). It was supposed to be on the rock Souffle. Details of all this are in the text of my book but we won't go into them here. Where did the sol 23 drive end? Tomorrow we are going to need a new map to show it.
#mars #marspathfinder

The second part of the Sojourner route map covers the same area as the first part. Sojourner drove back to the area below the ramp for some more work Then on sol 23 it drove east, past Scooby Doo and out of the right edge of the map. I separated these activities from the previous set for clarity, showing the older path faintly to tie the two together. What about APXS measurement A11? I don't show where the sensor was placed. Did I just forget to show it?
#maps #mars #marspathfinder

The second part of the Sojourner route map covers the same area as the first part. Sojourner drove back to the area below the ramp for some more work Then on sol 23 it drove east, past Scooby Doo and out of the right edge of the map. I separated these activities from the previous set for clarity, showing the older path faintly to tie the two together. What about APXS measurement A11? I don't show where the sensor was placed. Did I just forget to show it?
#maps #mars #marspathfinder

Just off the ramp on sol 2 we see a text box saying 'sol 2: A2'. The black dot shows the location of the end of the drive on that sol, and we learn that the second APXS measurement was made there (A1 was a test on the lander). Just above it a small box is also labelled A2 - that is the actual location of the sensor, so it was a soil measurement. A3 was on a rock. Keep in mind the rover is bigger than those dots! They took 2 attempts to get one on Yogi.
#mars #marspathfinder

Just off the ramp on sol 2 we see a text box saying 'sol 2: A2'. The black dot shows the location of the end of the drive on that sol, and we learn that the second APXS measurement was made there (A1 was a test on the lander). Just above it a small box is also labelled A2 - that is the actual location of the sensor, so it was a soil measurement. A3 was on a rock. Keep in mind the rover is bigger than those dots! They took 2 attempts to get one on Yogi.
#mars #marspathfinder

Just off the ramp on sol 2 we see a text box saying 'sol 2: A2'. The black dot shows the location of the end of the drive on that sol, and we learn that the second APXS measurement was made there (A1 was a test on the lander). Just above it a small box is also labelled A2 - that is the actual location of the sensor, so it was a soil measurement. A3 was on a rock. Keep in mind the rover is bigger than those dots! They took 2 attempts to get one on Yogi.
#mars #marspathfinder

Just off the ramp on sol 2 we see a text box saying 'sol 2: A2'. The black dot shows the location of the end of the drive on that sol, and we learn that the second APXS measurement was made there (A1 was a test on the lander). Just above it a small box is also labelled A2 - that is the actual location of the sensor, so it was a soil measurement. A3 was on a rock. Keep in mind the rover is bigger than those dots! They took 2 attempts to get one on Yogi.
#mars #marspathfinder

Just off the ramp on sol 2 we see a text box saying 'sol 2: A2'. The black dot shows the location of the end of the drive on that sol, and we learn that the second APXS measurement was made there (A1 was a test on the lander). Just above it a small box is also labelled A2 - that is the actual location of the sensor, so it was a soil measurement. A3 was on a rock. Keep in mind the rover is bigger than those dots! They took 2 attempts to get one on Yogi.
#mars #marspathfinder

This is the first section of the Sojourner rover's route map. The lander bounced and rolled across the surface until it came to rest. It deflated its airbags and unfolded - the airbags are still visible around the lander base. On sol 1 Sojourner was on the lander. On sol 2 it drove off, and here we can follow it across the surface. Its APXS instrument was on a short arm which could be rotated down to touch the target - soil or rock (A1, A2 and so on).
#maps #mars #marspathfinder

This is the first section of the Sojourner rover's route map. The lander bounced and rolled across the surface until it came to rest. It deflated its airbags and unfolded - the airbags are still visible around the lander base. On sol 1 Sojourner was on the lander. On sol 2 it drove off, and here we can follow it across the surface. Its APXS instrument was on a short arm which could be rotated down to touch the target - soil or rock (A1, A2 and so on).
#maps #mars #marspathfinder

This is the first section of the Sojourner rover's route map. The lander bounced and rolled across the surface until it came to rest. It deflated its airbags and unfolded - the airbags are still visible around the lander base. On sol 1 Sojourner was on the lander. On sol 2 it drove off, and here we can follow it across the surface. Its APXS instrument was on a short arm which could be rotated down to touch the target - soil or rock (A1, A2 and so on).
#maps #mars #marspathfinder

This is the first section of the Sojourner rover's route map. The lander bounced and rolled across the surface until it came to rest. It deflated its airbags and unfolded - the airbags are still visible around the lander base. On sol 1 Sojourner was on the lander. On sol 2 it drove off, and here we can follow it across the surface. Its APXS instrument was on a short arm which could be rotated down to touch the target - soil or rock (A1, A2 and so on).
#maps #mars #marspathfinder

This is the first section of the Sojourner rover's route map. The lander bounced and rolled across the surface until it came to rest. It deflated its airbags and unfolded - the airbags are still visible around the lander base. On sol 1 Sojourner was on the lander. On sol 2 it drove off, and here we can follow it across the surface. Its APXS instrument was on a short arm which could be rotated down to touch the target - soil or rock (A1, A2 and so on).
#maps #mars #marspathfinder

This set of images concludes our coverage of Sojourner's adventures. It's a pretty good way to tell the story, I think. If several images of the rover were taken in one sol, they are combined in one image. If only one image was taken it is the end of drive image.

OK - now let's start putting this on a map. The map of the site I showed earlier with all the rock names will be the base image, but enlarged and covered in several sections.
#mars #marspathfinder

This set of images concludes our coverage of Sojourner's adventures. It's a pretty good way to tell the story, I think. If several images of the rover were taken in one sol, they are combined in one image. If only one image was taken it is the end of drive image.

OK - now let's start putting this on a map. The map of the site I showed earlier with all the rock names will be the base image, but enlarged and covered in several sections.
#mars #marspathfinder

This is the 4th set of Sojourner rover images, taking us from sol 37 to sol 60. In the middle of the sequence the rover got itself in a very awkward position up on some rocks, and it took some considerable care and expertise to get it off safely. The T for technology tests were a variety of driving and maneuverability tests. The point here is, as you can see, they made the most of this little rover.
#mars #marspathfinder

This is the 4th set of Sojourner rover images, taking us from sol 37 to sol 60. In the middle of the sequence the rover got itself in a very awkward position up on some rocks, and it took some considerable care and expertise to get it off safely. The T for technology tests were a variety of driving and maneuverability tests. The point here is, as you can see, they made the most of this little rover.
#mars #marspathfinder

Sol 29 in that image has an asterisk to indicate that the activity took place on sol 29 but the images were taken on sol 30. I found I could work with these images and the map we saw earlier to put the rover locations and route unambiguously on a map, improving on what could be done at the time. We will get to that after the next 2 pages of these rover images.
#mars #marspathfinder

Sol 29 in that image has an asterisk to indicate that the activity took place on sol 29 but the images were taken on sol 30. I found I could work with these images and the map we saw earlier to put the rover locations and route unambiguously on a map, improving on what could be done at the time. We will get to that after the next 2 pages of these rover images.
#mars #marspathfinder

Sojourner's sols 24-36 in the same format. I made the rover stand out by increasing contrast relative to the rest of each image. For scale in these figures, Sojourner is 63 cm long, 48 cm wide and 28 cm high. W denotes wheel abrasion experiments, which involved rotating just the right middle wheel of the rover. It carried nickel, platinum and aluminum plates. As the wheel turned the amount of wear was estimated from changes in reflectivity measured by a light sensor.
#mars #marspathfinder

Sojourner's sols 24-36 in the same format. I made the rover stand out by increasing contrast relative to the rest of each image. For scale in these figures, Sojourner is 63 cm long, 48 cm wide and 28 cm high. W denotes wheel abrasion experiments, which involved rotating just the right middle wheel of the rover. It carried nickel, platinum and aluminum plates. As the wheel turned the amount of wear was estimated from changes in reflectivity measured by a light sensor.
#mars #marspathfinder

Here is the next section of the Pathfinder mission story - What Sojourner did between sols 15 and 23. These panels show motions and annotations indicate where various experiments were made. Soil mechanics experiments involved keeping 5 wheels fixed and rotation the sixth to estimate how hard the surface was. APXS measured composition. We will look at more measurements later.
#mars #marspathfinder

Here is the next section of the Pathfinder mission story - What Sojourner did between sols 15 and 23. These panels show motions and annotations indicate where various experiments were made. Soil mechanics experiments involved keeping 5 wheels fixed and rotation the sixth to estimate how hard the surface was. APXS measured composition. We will look at more measurements later.
#mars #marspathfinder

Pathfinder didn't just image tracks, it also imaged the rover itself, and here it was much more systematic. I started to put together sets of images to document sol by sol movements, to help with the mapping, and then realized just how useful it was to document the rover's activities like this. Here's the first page of images, like a storyboard for the mission. I will be doing this soon, I hope, for rovers on CLPS landers on the Moon.
#mars #marspathfinder

Pathfinder didn't just image tracks, it also imaged the rover itself, and here it was much more systematic. I started to put together sets of images to document sol by sol movements, to help with the mapping, and then realized just how useful it was to document the rover's activities like this. Here's the first page of images, like a storyboard for the mission. I will be doing this soon, I hope, for rovers on CLPS landers on the Moon.
#mars #marspathfinder

And here is a very quick and dirty reprojection of it into a very crude map, not controlled properly but just to show what it might look like.
#maps #mars #marspathfinder

And here is a very quick and dirty reprojection of it into a very crude map, not controlled properly but just to show what it might look like.
#maps #mars #marspathfinder

Here is a version reduced in size but with tracks highlighted in orange - I just made this very quickly now for this post so it is sketchy, but it is a start. Not really a lot better than that JGR map! I could have just projected this onto my map but I didn't, i used it as a guide for what follows.
#mars #marspathfinder

Here is a version reduced in size but with tracks highlighted in orange - I just made this very quickly now for this post so it is sketchy, but it is a start. Not really a lot better than that JGR map! I could have just projected this onto my map but I didn't, i used it as a guide for what follows.
#mars #marspathfinder

My first step was to take one of the panoramas the mission team released and paste onto it every image from the lander camera which showed tracks. This is not a perfect record: some bits of track were not imaged, if the wheels were on rocks they didn't leave tracks, and in the south they were too far away to show clearly. But it's a start. Here is that panorama . You have to look closely at a full size version to see the tracks.
#mars #marspathfinder

My first step was to take one of the panoramas the mission team released and paste onto it every image from the lander camera which showed tracks. This is not a perfect record: some bits of track were not imaged, if the wheels were on rocks they didn't leave tracks, and in the south they were too far away to show clearly. But it's a start. Here is that panorama . You have to look closely at a full size version to see the tracks.
#mars #marspathfinder

Why the gaps? They are caused by dead reckoning errors which built up during each drive, followed by a reset position based on post-drive imaging. But instead of correcting the faulty path to bring it to the right place, the map was just left with these gaps. I resolved to do better. There was a second map in that paper:

https://www.jpl.nasa.gov/images/pia01238-mars-pathfinder-rover-traverse-image/

Which looks much better but is not in a standard map geometry (i.e. you can't measure the lengths of its drives).
#mars #marspathfinder

Why the gaps? They are caused by dead reckoning errors which built up during each drive, followed by a reset position based on post-drive imaging. But instead of correcting the faulty path to bring it to the right place, the map was just left with these gaps. I resolved to do better. There was a second map in that paper:

https://www.jpl.nasa.gov/images/pia01238-mars-pathfinder-rover-traverse-image/

Which looks much better but is not in a standard map geometry (i.e. you can't measure the lengths of its drives).
#mars #marspathfinder

This map is from the summary paper by Matt Golombek et al.:

Golombek et al., 1999. Overview of the Mars Pathfinder Mission: Launch through landing, surface operations, data sets, and science results. JGR Planets, 104(E4), pp.8523-8553.

It is here: https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/98JE02554

(I hope everyone can get it, I think it's open now).

The rover route is mapped but it is discontinuous. The figure caption in the paper explains it...
#maps #mars #marspathfinder

This map is from the summary paper by Matt Golombek et al.:

Golombek et al., 1999. Overview of the Mars Pathfinder Mission: Launch through landing, surface operations, data sets, and science results. JGR Planets, 104(E4), pp.8523-8553.

It is here: https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/98JE02554

(I hope everyone can get it, I think it's open now).

The rover route is mapped but it is discontinuous. The figure caption in the paper explains it...
#maps #mars #marspathfinder

Now we have a map which can be used to trace the route of the little rover, Sojourner. The boundaries of that map are set to encompass the entire path followed by the rover. Before we start looking at this, let's see how the rover route was mapped at the time of the mission. Tomorrow!
#mars #marspathfinder

Now we have a map which can be used to trace the route of the little rover, Sojourner. The boundaries of that map are set to encompass the entire path followed by the rover. Before we start looking at this, let's see how the rover route was mapped at the time of the mission. Tomorrow!
#mars #marspathfinder

Here is a map of the Pathfinder landing site which uses HiRISE (greatly enlarged) as a base image and drapes a polar projection of the panorama over it, using lots of rocks as tie points. Some of the rocks are partially rectified in a very ad hoc manner to reduce the radial stretching which a pure polar projection creates. The interiors of the two swales (depressions) were not seen by the lander. Lots of features are named, most from cartoon characters.
#maps #mars #marspathfinder

Here is a map of the Pathfinder landing site which uses HiRISE (greatly enlarged) as a base image and drapes a polar projection of the panorama over it, using lots of rocks as tie points. Some of the rocks are partially rectified in a very ad hoc manner to reduce the radial stretching which a pure polar projection creates. The interiors of the two swales (depressions) were not seen by the lander. Lots of features are named, most from cartoon characters.
#maps #mars #marspathfinder

The result isn't perfect but it's a start. Areas hidden from the camera - depressions - are omitted from the projected image. This version of the method uses a thin plate spline approach to force tie points to exact locations, but it misbehaves where there are no tie points. If you see those elongated rock images swirling away from radial to the lander, that's the spline having a fit. Closer to the lander it works pretty well as we will see tomorrow.
#mars #marspathfinder

The result isn't perfect but it's a start. Areas hidden from the camera - depressions - are omitted from the projected image. This version of the method uses a thin plate spline approach to force tie points to exact locations, but it misbehaves where there are no tie points. If you see those elongated rock images swirling away from radial to the lander, that's the spline having a fit. Closer to the lander it works pretty well as we will see tomorrow.
#mars #marspathfinder

Here we begin the process of making a new map of the Pathfinder landing site. Again we are comparing a HiRISE image (top) with the projected mosaic, except that a new kind of projection is used. Here I tried to match individual features - mostly rocks - between the 2 images and used them as tie points to warp the panorama to fit HiRISE. This was impossible during the mission as HiRISE was not built yet. THere were about 200 tie points.
#maps #mars #marspathfinder

Here we begin the process of making a new map of the Pathfinder landing site. Again we are comparing a HiRISE image (top) with the projected mosaic, except that a new kind of projection is used. Here I tried to match individual features - mostly rocks - between the 2 images and used them as tie points to warp the panorama to fit HiRISE. This was impossible during the mission as HiRISE was not built yet. THere were about 200 tie points.
#maps #mars #marspathfinder

This is another map made at the same time, using images made only just after the rover moved off the lander, so no tracks out to the rock. On it someone at JPL plotted wind tails - little streaks of dust trailing behind many of the rocks, large and small. They show the direction of the prevailing winds. Also, areas hidden behind the lander panels, rocks or local ridges are masked out in purple. North is at the top - it was not in the previous map.
#maps #mars #marspathfinder

This is another map made at the same time, using images made only just after the rover moved off the lander, so no tracks out to the rock. On it someone at JPL plotted wind tails - little streaks of dust trailing behind many of the rocks, large and small. They show the direction of the prevailing winds. Also, areas hidden behind the lander panels, rocks or local ridges are masked out in purple. North is at the top - it was not in the previous map.
#maps #mars #marspathfinder

Here is the middle bit of that map at full resolution. Luckily I have saved all this stuff! My digital archive starts in 1996. It would be possible to modify each rock image to reduce the distorted appearance but that is very time-consuming. These days AI - no, let's not go there. Notice the tracks leading from the rover ramp out to the rock Yogi, and little Sojourner placing its APXS instrument on the rock.
#maps #mars #marspathfinder

Here is the middle bit of that map at full resolution. Luckily I have saved all this stuff! My digital archive starts in 1996. It would be possible to modify each rock image to reduce the distorted appearance but that is very time-consuming. These days AI - no, let's not go there. Notice the tracks leading from the rover ramp out to the rock Yogi, and little Sojourner placing its APXS instrument on the rock.
#maps #mars #marspathfinder

This is an example of a map made for mission operations in 1997, a panorama projected out onto a flat surface. This did not yet take relief into account so there are some distortions. Get any distance away from the lander and the landscape is almost lost in a forest of elongated rock images. Because the top of a rock is higher in the panorama than the bottom it is interpreted as being further away.
#maps #mars #marspathfinder

This is an example of a map made for mission operations in 1997, a panorama projected out onto a flat surface. This did not yet take relief into account so there are some distortions. Get any distance away from the lander and the landscape is almost lost in a forest of elongated rock images. Because the top of a rock is higher in the panorama than the bottom it is interpreted as being further away.
#maps #mars #marspathfinder

Now we are going to spend some time thinking about mapping the landing site. That circular panorama is a step in that direction. But the comparison between it and the orbital image could not be done (except for distant hills) at the time (1997) because high resolution orbital images of the site were not available. The panorama and maps made from it were all that could be used to plan mission operations. #mars #marspathfinder